尖牙

Department of tooth crowns were removed and apical, dedicated root 6mm long, 50 teeth set up Enterococcus faecalis after root canal infection model, 20 teeth were placed in root canals cinnamaldehyde, gallnut decoction, Another 30 infected root canals placed FC, calcium hydroxide paste propylene glycol and normal saline.

标本牙去除牙冠部及根尖部，留取6mm长牙根，50颗牙建立粪肠球菌根管感染模型后，20颗牙根管内分别放置桂皮醛、五倍子水煎剂，另30颗感染根管放置FC、氢氧化钙丙二醇糊剂和生理盐水。

Methods The majority patients were Corrected with edgewise appliance after draw four molars, all sorts of flexure were curved on the appliance, used perpendicular traction for anterior teeth and II, III maxillomandibular traction, fine adjust intercuspal position ,tip and cavity.

多数患者采取拔除4个磨牙之后使用方丝弓矫治器矫治，矫治中在弓丝上弯制各种曲，并使用前牙垂直牵引和颌间Ⅱ类、Ⅲ类牵引，精调牙位及尖窝关系。

Methods: 124 teeth of 109 patients with pulpitis and chronic periapical periodontitis requiring root canal therapy were included in this study.

将109例患者124颗患牙(包括牙髓炎、慢性根尖周炎)随机分为2组，每组62颗牙。

METHODS:Treatment records of 1100 teeth with acute or chronic pulpitis or chronic apical periodontitis were compared.

选择患急、慢性牙髓炎和慢性根尖周炎 80 0例 110 0个患牙，随机分为两组，对照组 5 14牙采用常规根管治疗术即两次法，实验组 5 86牙采用一次法进行根管充填，观察各组术后近期临床反应。

MTA was an ideal material for management of pulpless permanent teeth with incomplete root formation.

临床观察MTA治疗根尖发育不全并无髓牙和穿孔延迟修补的效果，对前一类病例用MTA制备根尖屏障，在控制感染后，患者仅需来诊1～2次即可完成治疗，7例中有5例根尖暗影完全消失，2例明显缩小，取得了明显的效果。

After 8 weeks growth, the polarization became more obvious in the pre-ameloblast and pre-odontoblast. Cells became high stylolitic shape and small amounts of dentin formation were found in the future of dental cusp region.

生长8周时，前成釉质细胞和前牙本质细胞的极化变得更加明显，细胞已变成高柱状，在未来牙尖区域可发现少量牙本质的形成。

The occurrence of the apical lateral foramina is 15.31%(230/1502).Conclusions The apical lateral foramina are found in 1/7 of 1 502 permanent teeth.

恒牙根尖部侧孔的孔径为根尖孔的一半，并约有1/7的恒牙出现根尖部侧孔。

Place short and long food chips in posterior occlusion of unilateral left side. When the masticated load was 3、5、7 kg, the displacement of abutments was measured by a LB-high sensitive laser transferring detector to calculate displacement, inclination and torsion of the abutment in mesial-distal, labial lingual and vertical and horizontal directions.

分别在左侧后牙区放置长、短食物片的咬合状态下，负载3 kg、5 kg、7 kg咬合力时，用高精度半导体激光位移测量仪测量并计算出同侧基牙在近远中向、颊舌向的水平位移和倾斜、垂直向的位移和水平旋转，统计分析不同牙尖斜度对基牙位移的影响。

Results: Before the fixed bridge was applied, under vertical load, the high-stress region was near around the apical of periodontal ligament with mainly compressive stresses. Under oblique load, the high-stress region was near around the cervical of periodontal ligament with both tensile and compressive stresses. After the fixed prosthodontics, stress and strain distributions were similar with that when the fixed bridge was not applied. But the maximum stress, strain and displacement increased apparently. The stresses in exterior surface of periodontal ligament were larger than that of interior surface; this character of periodontal ligament under vertical load was more obvious than that under oblique load.

结果：固定桥修复前，垂直载荷下，基牙牙周膜的应力以压应力为主，应力集中在根尖；斜向载荷下，基牙牙周膜的应力主要是拉应力和压应力，应力集中在唇、舌颈缘；固定桥修复后，基牙牙周膜的应力和应变分布规律与修复前相似，但最大应力、应变值都明显增大；牙周膜内表面的应力大于牙周膜外表面；垂直载荷时，牙周膜内、外表面的应力差异更为显著。

Methods: 60 freshly extracted , single-rooted premolars were randomly divided into two experimental groups (cinnamic aldehyde, gallnut decoction) and four control group (FC group, calcium hydroxide mixed with propylene glycol group, negative the control group and positive control group),.

标本牙去除牙冠部及根尖部，留取6mm长牙根，50颗牙建立粪肠球菌根管感染模型后，20颗牙根管内分别放置桂皮醛、五倍子水煎剂，另30颗感染根管放置FC、氢氧化钙丙二醇糊剂和生理盐水。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。